Embedded magnet type motor

Abstract

A rotor of an embedded magnet type motor is disclosed. A rotor core of the motor includes first accommodation holes and V-shaped accommodation holes The first accommodation holes extend in radial directions, and the V-shaped accommodation holes protrude radially outward. The rotor core has grooves at positions corresponding to the first accommodation holes on the outer periphery of the rotor core. Each groove has a width as a dimension in the circumferential direction when viewed from the axial direction. Each first magnet has a width as a dimension in the circumferential direction when viewed from the axial direction. The width of the grooves is larger than the width of the first magnets.

Description

BACKGROUND OF THE INVENTION[0001]The present invention relates to an embedded magnet type motor.[0002]Conventionally, a rotor core of an embedded magnet type motor has a plurality of accommodation holes aligned in the circumferential direction, and the accommodation holes perforate through the rotor core axially. In the accommodation holes, magnets are accommodated.[0003]In the embedded magnet type motor disclosed in Japanese Laid-Open Patent Publication No. 2005-51982, each of a plurality of magnetic poles includes a pair of magnets arranged in a V shape to protrude radially inward. Specifically, when the number of magnetic poles of the embedded magnet type motor is P, the number of magnets is 2 P. With this construction, a higher torque can be realized in comparison with a motor in which one magnet is provided per one magnetic pole.[0004]However, when two magnets are provided per one magnetic pole, the number of parts increases and parts management cost and assembly cost also incr...

AI Technical Summary

Benefits of technology

"The present invention provides an embedded magnet type motor that increases torque while reducing leakage fluxes. This is achieved by designing a rotor with a plurality of accommodation holes that perforate the rotor core along the axial direction. The accommodation holes include first accommodation holes and V-shaped accommodation holes. The first magnets, second magnets, and third magnets constitute one magnetic pole, and each magnetic pole has a corresponding hole portion in the rotor core. The width of the hole portions is larger than the width of the first magnets. This design allows for a more efficient use of magnetic materials and reduces the number of parts."

Problems solved by technology

However, when two magnets are provided per one magnetic pole, the number of parts increases and parts management cost and assembly cost also increase.

Therefore, leakage fluxes passing through the outer bridges are excessive as a whole of the motor.

This reduces the effective fluxes of the embedded magnet type motor and obstructs the torque increase.

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